Motor oil pressure safety ignition switch



Sept. l, 1959 E. L. GALLIER y' MOTOR OIL PRESSURE SAFETY IGNITION SWITCH Filed Nov. 14, 1955 Y.. fx

United States Patent O MOTOR OIL PRESSURE SAFETY IGNITION SWITCH Edwin L. Gallier, Chicago, Ill.

Application November 14, 1955, Serial No. 546,355

9 Claims. (Cl. 12S-146.5)

This invention relates to the circulation of lubricating oil under pressure and more particularly to an alarm system for opening the ignition circuit of an engine when the oil pressure is too low.

This invention is particularly described in connection with an internal combustion engine having an oil circulation system and includes a key operated device for manually closing a circuit which is maintained in closed position by predetermined pressure from the oil supply systern of the engine and the ignition system for the engine is automatically opened at any time that the oil pressure reaches a predetermined low pressure.

An important object of the invention is to provide a key operated device which will close an ignition circuit and has pressure operated means for maintaining the ignition circuit in a closed position.

" A still further object of the invention is to provide a keytoperated device for closing the ignition circuit which eliminates the necessity of an oil gage and the key itself indicates proper oil pressure when the engine is running.

A still further object of the invention is to provide a switch device in which the ignition key will automatically return to the off position and indicate that the ignition system is shut off, thereby preventing damage to the enlginebearings and all lubricated engine parts, and also protecting all ignition parts.

Still a further object of the invention is to provide an indicator in connection with the operating key which shows by the position of the key that the switch device is in engine running or idle position.

Still a further object-of the invention is to provide a removable key in order to stop the engine which is otherwise in satisfactory operating condition so far as oil pressure is concerned, as an added safety factor and a protection against theft.

*I Other objects of the invention will appear in the specication and will be more apparent from the accompanying drawings, in which Figs. 1 and 2 are end and side elevations of a switch device in accordance 4with this invention.

Fig. 3 is an end elevation of the device from the end opposite that shown in Fig. l.

Fig. 4 is a detail sectional view as taken on the line 4 4 of Fig. 2.

' Fig. 5 is a detail sectional view taken on the line 5--5 of Fig. 2.

Fig. 6 is a longitudinal section taken on the line 6 6 of Fig. 3.

yIFg. 7 is Va diagrammatic view showing an internal combustion engine ignition system incorporating the switch of the present invention; and

Fig. 8 is a diagrammatic view of a modification of a portion of the system shown in Fig. 7.

In this system, the safety ignition switch may be substituted for the ordinary ignition switch or it may be used in conjunction therewith. lf used in connection with an ordinary ignition switch, the latter will have no effect until ICC must be held momentarily in closed position until the motor starts building up the engine oil pressure after a few turns of the engine to hold the safety ignition switch in closed position.

Referring now more particularly to the drawings, the switch device comprises a unitary casing 10 formed of suitable metal and includng a longitudinally extending bore 12 in which a plunger 14 is movable near one end of the bore. A groove 16 is formed in the plunger near the outer end thereof for seating a gasket or pressure ring 18 in the groove so that the plunger is in effect a fluidtight piston. This end of the casing has internal threads 20 for securing a iluid pressure pipe 22 therein for operating the piston and plunger.

At the other end of the plunger is a reduced stem 24 which carries an insulating sleeve 26 thereon of ber or other suitable material. One end of the sleeve has a reduced portion 28 upon which a metal conducting washer 30 is mounted for limited free movement against a shoulder of the insulating sleeve and at the outer end of this reduced portion 28 is a washer 32 of insulating material for engaging one end of a coil spring 34 which surrounds the reduced portion 23 and bears against the metal washer 30 so that it is capable of a limited movement on the reduced portion against the spring 34.

At the other end of the insulating sleeve 25 is a reduced portion 36 forming a shoulder on the sleeve 26 which is abutted by one end of a coil spring 3S which is mounted upon the reduced portion 36 and projects outwardly. The outer end of the coil spring 38 extends into a hollow plug 40 threaded into an enlarged bore 42 of the casing forming a continuation and opposite termination of the bore 12. The outer end of the plug 40 has internal threads 44 engaged by a plug screw 46 having an inner stem 48 which is concentric with the reduced portion 36 of the insulating sleeve and forms an outer seating and centering projection for the projecting end of the coil spring 38. Thus the spring 38tends to press the plunger 14 outwardly in the bore 12 against the indicating pressure of oil or any other uid in the pipe 22.

Extending oppositely from the enlarged bore 42 of the casing are short hollow casing extensions 50 and 52 in which insulating fiber shells 54 are tightly inserted, each preferably with a collar 56 at its outer end to abut the outer end of the shell extension. In these insulating shells, conductor contact pins 58 and 60 are tightly inserted and the inner ends may abut the intermediate portion of the insulating sleeve 26 which is larger than the reduced ends thereof to limit the insertion of the pins which are in the path of the metal washer 30 mounted at one end of the sleeve for the purpose of electrically joining the contacts 58 and 60 when the sleeve 26 and the safety switch is also operated and the safety switch the plunger 14 are moved against the pressure of the spring 38. At this time, the spring 34 will press the conducting washer 30 against the ends of the pins 5S and 60 to make an electrical connection between them. The outer ends of the contact pins 58 and 60 may be threaded for the attachment of conductors and fastening means therefor, and the threaded ends each have a shoulder 62 which limits its insertion into its insulated shel1 54.

To move the plunger 14 in the casing, one portion of the plunger is provided with teeth forming a rack 64 which is engaged by a pinion 66 formed on one end of a short stem 68 having a thread 70 at the other end. The casing 10 is provided with a short hollow extension 72 for receiving a lock barrel 74 which is actuated by a key 76 inserted at the outer end of the lock in a well known manner. The inner end of the lock barrel which is rotatable with the key is attached to the short stem 68 by threading the stem into the adjacent end of the lock barrel. The lock barrel is seated in the extension 72 in a well known manner by inserting a pin 78 through the casing. extension 72 into a groove 8,0 ofthe lock barrel. This allows the lock to turn in the casing by the operation of a proper key.

At the outside of the casing extension 72 is a lock plate 82 -having several designations on the face thereof such as. a verticall line 84 indicating the off position, a horizontal line 86 indicating on or running position and an intermediate line 8S which may indicate an idle position in which the engine is operated at reduced speed.

In` operation, this safety switch is turned from the off to the on position by the key 76 against the pressure of the spring 3S until the contact washer 30 engages the two contact pins 5S and 60 closing an electrical connection between them. If the pressure which enters through a pipe 22 is suflicient to continuously overcome the closing pressure yof they spring 3S, the switch will` be maintained in closed position as above described, but if the pressure falls for any reason, the spring 33 will cause the plunger to rotate the key reversely, thereby breaking electrical connection between the Contact pins 58 and 60.

If the speed of the engine is reduced so that the oil pressure is also reduced, the pressure of the spring 34 in addition to the oil pressure may be sufficient to oppose a substantial balance, the spring 38 maintaining the conducting Washer 30 in a limited yielding engagement with the contact pins S8' and 60, thereby allowing a limited movement of the plunger 14 and its rack 64, and the key 76 to the intermediate position as indicated by idle in Fig. 2 and keeping the engine operating circuit closed.

To shut off the engine manually, the key is turned to off position against the oil pressure on the plunger. Since the pressure is partly balanced by the spring 355, no great turning pressure on the key is required to make the change.

The casing extension 72 carrying the lock barrel 74 has threads 73 on the outside upon which lock nuts 75 are adjustable for fastening the safety switch casing 10 in any desired location, as on an instrument board or panel with the key lock plate 82 in outside accessible position for the insertion of the key 76.

The spring 34 presses the conductor washer 30 to make a yielding contact as soon as the key is partially rotated and the key may be retained in an intermediate position indicating an idling movement of an engine to which the switch is attached. The lock may also be formed so that the key cannot be withdrawn from the lock until the switch is in the off position which is an added safety factor for insuring that a motor will not be kept running when the key is removed.

When this safety ignition switch is applied to an internal combustion engine 90 as represented in Fig. 7, an oil pump 91 is operated by the engine and is connected by means of a pipe 22 to the safety switch which carries a contact washer 30 for making connection between the fixed pin contacts 58 and 60.

The ignition circuit from a battery 92 to one of the contacts 60 may be controlled by an ordinary key operated starting switch 93 and conductors 94, and the contact pin 58 may be connected to an ignition coil 95 by a conductor 96. The ignition coil is connected to a distributor 97 by a conductor 98, and the distributor is conneeted to the engine cylinders in a well known manner. The safety switch mechanism is represented by a plunger 14a having a rack 64a engaged by a key operated pinion 66a. The plunger has a piston 14b operating in a passage 12a which receives pressure from the pump 91 through the pipe 22. The plunger is urged against the pressure transmitted by the pipe 22 by a spring 38a.

In the modification shown by Fig. 8, additional back contacts 100 and 102 are provided, one of which is connected by a conducto-r 104 with the conductor 94 extending to the battery 92, and the washer 30 upon its return movement from engagement with the pins 58 and 60 will close the circuit from the battery through conductors 94, between the contacts 100 and 102 and from contact 100 through conductors 104 and a signal lamp 106 (or an audible signal) to a ground connection.

An electric starting motor 108 is provided for the enlgine which operates in a well known manner and receives current through a conductor 110 connected to the ignition coil conductor 96 so that it will receive current as soon as the safety starterr switch is closed.

In the operation of a system as shown in Fig. 7 or Fig. 8 as applied to an automobile engine for example, to start the engine the ordinary key starter switch 93, if there is one, is closed` and then the safety igniter switch is closed by turning the key 76. from the off position to the on or idling position as indicated by the on position 86 (or the idle. position 88,)1. At this time, a circuit is closed through the contact washer 30 between the contact pins 60 and 58 from the battery 92 through conductors 94 and 96 to the starting motor 103 through conductor 110 and also through coil 95 to the distributor 97 and from the distributor to the support engine cylinders in a well known manner.

The safety ignition switch is held in the idling or running position for a short time until the engine is started and an oil circulation, pressure is built up by the pump 91 which appears in the pipe 22 connected to the` passage 12a. This pressure engages the extremity 14C of the plunger 14a and is sufficient to hold the plunger to make contact with the contact washer 30 between the contact pins 58 and 60 against the pressure of the spring 38a, thus maintaining the ignition circuit through the coil and distributor in a well known manner. The circuit to the starting motor isautomatically broken as soon as the engine starts :in accordance with presentl operation practice.

In the construction, shown by Fig. 8, the operation is the same as that described' in connection with Fig. 7 with the exception that when the oil pressure fails, for any reason which may be due to the absence of oil or lack of its circulating, the pressure on the end 14c of the plunger is so reduced that the spring 38a will cause a movement of the plunger 12a away from the contact pins 58 and 60 and will move the contact washer into engagement with contacts 100 and 102, thereby closing a circuit from the battery 92 through conductors 94 and the ordinary starter key 93, through conductor 104, contacts 100, 102 and contact washer 30, conductors 104 and signal lamp 106 (or any other signalling device) to a ground connection. In this system, a visible (or audible) signal is thus provided which will call the attention of the engine operato-r to the fact that the ignition circuit has been opened and that the engine is not operating. To restore the engine to running condition, the operator must determine whether there is sufficient oil in the engine crank case or whether there is some other oil line obstruction which should be corrected before the operation of the engine is continued.

In all cases ofv oil pressure failure to the safety switch, the igniter key will automatically return to the off position and thus will indicate that the ignition system is shut olf, thereby preventing damage to all lubricated engine parts which may be caused by improper lubrication and negligence on the part of an operator.

While a preferred embodiment of the invention has been described in some detail, it should be regarded as an illustration or example rather than as a limitation or restriction of the invention, since various changes in the construction, combination, and arrangement of the parts may be made without departing from the spirit and Scope of the invention.

I claim:

1. In a fluid pressure safety switch system, means for feeding fluid under pressure, a key operated switch having a plunger movable in both directions by the key to open and to close the switch manually, a spring opposing a movement of the plunger in one direction, a tubular member in which they plunger is pressed by said fluid feeding means against the pressure of the spring, electrical contacts on opposite sides of the plunger, and conducting means carried by the plunger for engaging the contacts when the key is turned to move the plunger against the spring and maintained in this position by a predetermined pressure of said fluid feeding means.

2. In a iluid pressure safety ignition switch system for internal combustion engines, an oil circulating pump for feeding fluid under pressure, a key operated switch including` a casing having a tubular portion and a plunger movable in both directions in the tubular portion by the key in closing and in opening the switch manually, a connection from the oil circulating pump to one end of the tubular portion and engaging one end of the plunger, a spring in the casing opposing the movement of the plunger in the direction urged byv iluid under pressure from the pump, an ignition circuit for the engine including spaced contacts in the casing adjacent the plunger, and electrical conducting means carried by the plunger for engaging the contact to close the circuit when the key is turned in one direction, the plunger holding the conducting means in closed position when suflicient pressure is maintained in the tubular portion by said pump, and the key movable to reverse the movement of the plunger breaking the ignition circuit.

3. In an engine oil pressure safety ignition switch system, a casing which receives oil under pressure when the engine is running, a tubular portion in the casing having a plunger movable therein under oil pressure from the engine, a spring in the casing opposing the movement of the plunger in the direction urged by the oil under pressure, a pair of contacts in the engine ignition circuit and adjacent the plunger in the casing, an electrical conducting means carried by the plunger for engaging the contacts when the plunger is moved against the spring pressure, and a key operated lock manually movable in reverse directions having means for engaging the plunger to move it in a direction to en-gage the conducting means with the contacts, the lock means being returnable with the plunger by the spring to disengage the conducting means when the pressure of the oil delivery by the pump is below a predetermined amount, and the plunger being movable by the lock means in the opposite direction from that urged by the oil under pressure to also separate said conducting means from the contacts.

4. In an engine oil pressure safety ignition switch, an oil pump, a casing having a tubular portion with a plunger therein for receiving oil pressure from the pump at one end of the plunger to move the plunger therein, a spring in the casing opposing the movement of the plunger by fluid pressure at the opposite end, a pair of contacts in the ignition circuit at opposite sides of the plunger and insulated from the casing, and electrical conductor carried by the plunger within the casing for engaging the contacts when the plunger is moved against the spring, a key operated lock having a rotatable barrel movable in opposite direction, and means for engaging the plunger to move it in one direction by the key against the spring and the conductor into engagement with the Xed contacts, the key and the plunger being returned by the spring pressure when the oil pressure against the plunger is reduced, and the key being also manually turned in reverse direction to open the connection between the contacts when there is sutlicient fluid pressure on the plunger to overcome the pressure of said spring.

5. A safety ignition switch structure in accordance with claim 4, in which the key operated barrel has a rack and pinion connection for manually moving the plunger in both directions and the key is held in closed position by the predetermined pressure against the plunger.

6. In an engine safety ignition switch an oil pump operated by the engine, a casing having a tubular portion with a plunger therein for receiving oil pressure from the pump at one end of the plunger to move the plunger therein,

a spring in the casing opposing the movement of the plunger by duid pressure at the opposite end, a pair of contacts in the ignition switch circuit at opposite sides of the plunger and insulated from the casing, an electrical conductor carried by the plunger within the casing for engaging the contacts when the plunger is moved against the spring, a key operated lock having a rotatable barrel movable in opposite directions and means for engaging the plunger to move it in one direction by the key against the spring and to move the conductor into engagement with the fixed contacts, the key and the plunger being returned by the spring pressure when the oil pressure against the plunger is reduced, and the key being also manually turnable in a reverse direction to open the connection between the contacts when there is sucient fluid pressure on the plunger to overcome the pressure of said spring, the key operated barrel having a rack and pinion connection for manually moving the plunger in both directions, and the key being held in closed position by predetermined pressure against the plunger, the lock having a key plate with indications for oth on and idle positions of the key and the key being insertable and removable only in the off position so that the key must be turned to open the ignition circuit to stop an engine and to remove the key from the lock.

7. In an engine safety switch system an oil pump operated by the engine, a casing having a tubular portion with a plunger therein for receiving oil pressure from the pump at one end of the plunger to move the plunger therein, a spring in the casing opposing the movement of the plunger by luid pressure at the opposite end, a pair of contacts in the ignition switch circuit at opposite sides of the plunger and insulated from the casing, an electrical conductor carried by the plunger within the casing for engaging the contacts when the plunger is moved against the spring, a key operated lock having a rotatable barrel movable in opposite directions and means for engaging the plunger to move it in one direction by the key against the spring and to move the conductor into engagement with the Xed contacts, the key and the plunger being returned by the spring pressure when the oil pressure against the plunger is reduced, and the key being also manually turnable in a reverse direction to open the connection between the contacts when there is suicient fluid pressure on the plunger to overcome the pressure of said spring, the key operated barrel having a rack and pinion connection for manually moving the plunger in both directions, and the key being held in closed position by predetermined pressure against the plunger, the combination with the ordinary contacts for closing a circuit and the conducting means therefo-r with a pair of back contacts for engaging the conducting means in the circuit opening movement of the plunger, and a circuit including the back contacts and a signal device for indicating that the ignition switch has been turned off.

8. In an engine safety ignition switch an oil pump operated by the engine, a casing having a tubular portion with a plunger therein for receiving oil pressure from the pump at one end of the plunger to move the plunger therein, a spring in the casing opposing the movement of the plunger by fluid pressure at the opposite end, a pair of contacts in the ignition switch circuit at opposite sides of the plunger and insulated from the casing, an electrical conductor carried by the plunger within the casing for engaging the contacts when the plunger is moved against the spring, a key operated lock having a rotatable barrel movable in opposite directions and means for engaging the plunger to move it in one direction by the key against the spring and to move the conductor into engagement with the fixed contacts, the key and the plunger being returned by the spring pressure when the oil pressure against the plunger is reduced, and the key being also manually turnable in a reverse direction to open the connection between the contacts when there is sufiicient fluid pressure on the plunger to overcome the pressure of said spring,

7 the conducting means carried by the plungerV comprising a metal Washer surrounding the plunger and a shoulder on the plunger on one side of the Washer against which it is seated, and a coil spring surrounding the plunger at thel other side of the washer and tending to press the Washer against the shoulder, the Washer engaging the fixed contacts against the pressure of said coil spring to make a resilient yielding connection of the Washer against the contacts which opposes the lirst spring which opposes the movement` of the plunger;

9; In an engine oil safety ignition switch system, the combination with an internal combustionengi-'ne having an oilpump, an ignition circuit including a battery, conductors from the battery to an ignition coil1 from the' ignition coil to a distributor and from a distributor to the engine cylinders, an ordinary lock switchV for` opening and closing the ignition' circuit, and an oil pressure safety switch having a casing with a movable plunger therein for receiving oil under presstue from the engine oil pump at one end of the plunger and` tending to. move the plunger oppositely in the casing, a spring in the casing opposing the movement of the plunger by the engine oil pressure, a pair of insulated contacts inthe casing and connected in the ignition circuit,v electrical Contact means carried by the plunger to make connection-V between the .contacts when the plunger is heldby the engine pump oill pressure, means in connection with the plunger for making a yielding connection with thecontacts, a keyl operated' barrel having an operating engagement withthe plunger to move it iin opposite directions and against the pressure of said spring, a key plate through which the key is inserted into the lock barrel having off andf on indications on the outer face of the plate, the key and itsy barrel.' being moved initially with the plunger to` on position to engage the contacting means with the xed insulated contacts to close the ignition circuit for the engine and maintained in this position momentarily until the engine starts, and the pump oilY pressure is applied against the end of the plunger barrel` to maintain the plunger inthe ignition circuit closing position unless theV oil pressure from the pump reaches a predetermined minimum, and,y the key and its barrel' being rotatable in a reverse direction to the off position to move the plunger andA its contacting means against said spring and` to open theignition circuit.

References Cited in thel le of this patent UNITED STATES PATENTS 1,362,685 Farah Dec. 2l, 1920 2,418,536 Wood Apr. 8', 1947 2,461,692 Malir Feb. 15, 1949 

